Who should reproduce?
Some people think that people over the age of thirty five should not reproduce. This is because women who become pregnant after the age of thirty five have a much higher chance of giving their children Down Syndrome, or other diseases involved with aging. Other people think that teenagers should not be able to reproduce because they cannot take care of their own body, so how are they able to care for a child of their own? It is scientifically been proven that women over the age of 35, and 40 have a much higher chance of giving their child a horrible disease, or raising children that innately have a lower intelligence that children born of 25 year old parents. It is also proven that teenagers don’t usually have the means, or the knowledge of how to properly care for themselves, and as a result, poorly affect their child’s health, and mental state. Although these perspectives on who should reproduce have some grain of truth to them, we can’t control people into thinking when the proper age is for children. Many adults also wait so long to have children, because they want to make sure that their children will be well cared for by their growing careers, and make sure that they are financially stable before they start to raise children. Some teens may actually also want to have children, because they are ready to become adults, and have always wanted to start a family. Either way, our society should not tell people what they can and can’t do, based on what they believe to be the proper thing to do.
Friday, July 27, 2007
Thursday, July 26, 2007
Unit IV Lab Project
Bacteria found in yogurt :
Scientific name ~ Lactobacillus bulgaricus
Common name ~ Bacteria in yogurt
Ecological principle ~ Commensal
This is considered a domesticated species because it is in our food
Scientific name ~ Lactobacillus bulgaricus
Common name ~ Bacteria in yogurt
Ecological principle ~ Commensal
This is considered a domesticated species because it is in our food
Golden retriever:
Scientific name ~ Canis familiaris
Common name ~ Golden retriever
Ecological principle ~ Symbiotic
This is considered a domesticated species because of evolution
Chow:
Scientific name ~ Canis familiaris
Common name ~ Chow chow
Ecological principle ~ Symbiotic
This is considered a domesticated species because of evolution
Green algae:
Scientific name ~ Halimeda cuneata
Common name ~ Green algae
Ecological principle ~ Commensal
This is considered a non-domesticated species because it grows freely outdoors
Pine tree:
Scientific name ~ pinus monticola
Common name ~ Pine tree
Ecological principle ~ mutualism
This is considered a domesticated species because we are able to have them in our yards.
Bananas:
Scientific name ~ Musa acuminata Colla
Common name ~ Banana
Ecological principle ~ Commensal
This is considered a domesticated species because it is in our food
Apple:
Scientific name ~ Malus domestica
Common name ~ Apple
Ecological principle ~ Commensal
This is considered a domesticated species because it is in our food
Cheese:
Scientific name ~ Caseus
Common name ~ Cheese
Ecological principle ~ Commensal
This is considered a domesticated species because it is in our food
Coffee:
Scientific name ~ Gymnocladus dioicus
Common name ~ Coffee
Ecological principle ~ Commensal
This is considered a domesticated species because it is in our food
Milk:
Scientific name ~ Silybum
Common name ~ Milk
Ecological principle ~ Commensal
This is considered a domesticated species because it is in our food
Deer:
Scientific name ~ Antilocapra Americana
Common name ~ Deer
Ecological principle ~ Commensal
This is considered a non-domesticated species because people don’t usually own them, they run free.
Chipmunks:
Scientific name ~ Eutamias
Common name ~ Chipmunk
Ecological principle ~ Commensal
This is considered a non-domesticated species because people don’t usually own them, they run free.
Cactus:
Scientific name ~ Peromyscus eremicus
Common name ~ Cactus
Ecological principle ~ mutualism
This is considered a domesticated species because it is a plant that
People can have, but usually grows freely outdoors.
Javalina:
Scientific name ~ Pecari tajacu
Common name ~ Javalina
Ecological principle ~ Commensal
This is considered a non-domesticated species, and people don’t own
These as pets.
Raccoon:
Scientific name ~ Procyon lotor
Common name ~ Raccoon
Ecological principle ~ Commensal
This is considered a non-domesticated species, and people don’t own
These as pets.
Skunk:
Scientific name ~ Conepatus mesoleucus
Common name ~ Skunk
Ecological principle ~ parasitic
This is considered a non-domesticated species because people don’t
Usually own these as pets, and avoid contact with them.
Squirrels:
Scientific name ~ Sciurus aberti
Common name ~ Squirrel
Ecological principle ~ Commensal
This is considered a non-domesticated species, because people don’t
Usually own squirrels as pets.
Pigeons:
Scientific name ~ Columba fasciata
Common name~ Pigeon
Ecological principle ~ Commensal
This is considered a non-domesticated species of bird, which people
Don’t usually own.
Roadrunner:
Scientific name ~ Geococcyx californianus
Common name ~ Roadrunner
Ecological principle ~ Commensal
This is considered a non-domesticated species of bird, which people
Don’t usually own
Coral snake:
Scientific name ~ Micruroides euryxanthus
Common name ~ Coral snake
Ecological principle ~ Commensal
This is considered a non-domesticated species of reptile, and people can,
But don’t commonly own these.
Quail:
Scientific name ~ Colinus virginianus
Common name ~ Quail
Ecological principle ~ Commensal
This is considered a non-domesticated species of bird, and people don’t
Commonly own these.
Coyote:
Scientific name ~ Canis latrans Say
Common name ~ Coyote
Ecological principle ~ Commensal
This is considered a non-domesticated version of a dog, which people
Don’t usually own.
Daisy:
Scientific name ~ Erigeron
Common name ~ Daisy
Ecological principle ~ mutualism
This is considered a domesticated plant species, people own these.
Juniper:
Scientific name ~ Juniperus
Common name ~ Juniper
Ecological principle ~ Commensal
This is considered a domesticated plant species, people can have these.
Mesquite:
Scientific name ~ Prosopis
Common name ~ Mesquite
Ecological principle ~ Commensal
This is considered a domesticated plant species, but is free also.
Ponderosa:
Scientific name ~ P. ponderosa
Common name ~ Ponderosa
Ecological principle ~ Commensal
This is considered a domesticated plant species, but is free also
Sagebrush:
Scientific name ~ Artemisia
Common name ~ Sagebrush
Ecological principle ~ Commensal
This is considered a domesticated plant species, but is free also
Spruce:
Scientific name ~ Picea
Common name ~ Spruce
Ecological principle ~ Commensal
This is considered a domesticated plant species, but is free also
Yucca:
Scientific name ~ Yucca schidigera
Common name ~ Yucca
Ecological principle ~ Commensal
This is considered a domesticated plant species and is used frequently
Grasshopper:
Scientific name ~ Trimerotropis melanoptera
Common name ~ Black-winged grasshopper
Ecological principle ~ Commensal
This is considered a non-domesticated species of insect because people don’t usually own as pets.
Cricket:
Scientific name ~ Anabrus simplex
Common name ~ Cricket
Ecological principle ~ Commensal
This is considered a non-domesticated species of insect because people don’t usually own as pets
Online lab activity #2 (Unit IV)
NOTE: Havin g trouble posting all pictures
1. What was your high fertility rate country and what was its fertility rate?
The United States. The fertility rate set at 10.2. What was your low fertility rate country and what was its fertility rate?
China. The fertility rate set at 2.3. The initial demographic "shape" of your high fertility rate country should have been a pyramid, with high population in young age groups. Explain why high fertility rate results in a high percentage of young people in the population. How does this affect future population growth?
When the fertility rate was increased, then the fertility rate results in a high percentage of young people in the population. This would affect future population growth because there would be more young people having children, and therefore the percentage of young people would continue to rise.4. Your low fertility rate country might have had a more oval-shaped curve with high population in middle age groups. This is especially exaggerated if the fertility rate is below 2.00. Explain why low fertility rate leads to lots of middle-aged people.
The set fertility rate was set at two, which can result in a high population in middle age groups. This would affect future population growth because there would be more adults, and therefore the percentage of children would decrease.5. Write ten adjectives or descriptive phrases for what you might expect life, people's attitudes, conditions on the streets, etc. will be like in each of those situations. Imagine a situation with lots of middle-aged and older people in the population and write ten quick "brain-storm" descriptors for you think it would be like (Prescott, Arizona?). Then do the same for a situation with lots of children in the population.
Younger population: Chaotic, crazy, immature, weird, riot, loud, noisy, disorganized, incompetent, confused.
1. What was your high fertility rate country and what was its fertility rate?
The United States. The fertility rate set at 10.2. What was your low fertility rate country and what was its fertility rate?
China. The fertility rate set at 2.3. The initial demographic "shape" of your high fertility rate country should have been a pyramid, with high population in young age groups. Explain why high fertility rate results in a high percentage of young people in the population. How does this affect future population growth?
When the fertility rate was increased, then the fertility rate results in a high percentage of young people in the population. This would affect future population growth because there would be more young people having children, and therefore the percentage of young people would continue to rise.4. Your low fertility rate country might have had a more oval-shaped curve with high population in middle age groups. This is especially exaggerated if the fertility rate is below 2.00. Explain why low fertility rate leads to lots of middle-aged people.
The set fertility rate was set at two, which can result in a high population in middle age groups. This would affect future population growth because there would be more adults, and therefore the percentage of children would decrease.5. Write ten adjectives or descriptive phrases for what you might expect life, people's attitudes, conditions on the streets, etc. will be like in each of those situations. Imagine a situation with lots of middle-aged and older people in the population and write ten quick "brain-storm" descriptors for you think it would be like (Prescott, Arizona?). Then do the same for a situation with lots of children in the population.
Younger population: Chaotic, crazy, immature, weird, riot, loud, noisy, disorganized, incompetent, confused.
Online lab activity #1 (Unit IV)
NOTE: I couldn't post the pictures, so I posted other pictures that I found.
List of significant events during fetal development:
1.) Fertilization is the process when the sperm and egg unit in one of the fallopian tubes to form a one-celled entity called a zygote.
2.) Second week
3.) This is significant because this is the period when the genetic material is sorted out, to determine what you will look like when you’re born.
4.) http://content.revolutionhealth.com/contentimages/images-image_popup-r7_fertilization.jpg
1.) Implantation is the time the zygote is made up of 500 cells, and is known as a blastocyst.
2.) Third week
3.) This is significant, because by the end of this week, you are able to tell if you are pregnant by a test.
4.) http://www.aapsj.org/articles/aapsj0802/aapsj080250/aapsj080250_figure4.jpg
1.) When the embryonic period begins, the baby’s brain, spinal cord, heart, and other organs begin to form.
2.) Fourth week
3.) This is significant because without the healthy development of these organs, the child could have problems throughout their entire lives.
4.) http://www.nonprofitpages.com/mcfl/Early.jpeg
1.) The baby’s heart will begin to beat, and the circulatory system is taking shape, and can be detected with an ultrasound.
2.) Fifth week
3.) This is significant because the heart is the most important organ, and needs to constantly checked (ultrasounds can help with this)
4.) http://health.yahoo.com/media/mayoclinic/images/slideshow/pr22_4chamber.jpg
1.) The neural tubes in a baby’s back are now closed, and a baby’s heart is beating with a regular rhythm.
2.) Sixth week
3.) This is significant because growth is one of the most rapid during this week of development.
4.) http://embryology.med.unsw.edu.au/Notes/images/neuron/image_002.gif
1.) The umbilical cord is the link between the baby and the placenta.
2.) Week 7
3.) This is important because this is when the baby is able to receive nutrients from the mother’s food and drinks.
1.) Baby’s fingers and toes start to form, wrists, elbows, and ankles are visible, and the baby’s eyelids are starting to form.
2.) Week 8
3.) This is important because the baby’s limbs are starting to forms
1.) Movement begins, and the embryonic tail at the bottom of the baby’s spinal cord is shrinking, and making them look more human.
2.) Week 9
3.) This is important because the baby can now connect with its mother by moving.
1.) Neurons multiply, and the baby’s vital organs have a solid foundation.
2.) Week 10
3.) This is important because the baby’s ears can start to form, and tooth buds are forming as well.
1.) A baby’s sex may be apparent, and its weight with multiply by thirty, and its length will triple.
2.) Week 11This is important because it is considered the “halfway” mark of conception, and the baby is now officially called a fetus.
1.) Fertilization is the process when the sperm and egg unit in one of the fallopian tubes to form a one-celled entity called a zygote.
2.) Second week
3.) This is significant because this is the period when the genetic material is sorted out, to determine what you will look like when you’re born.
4.) http://content.revolutionhealth.com/contentimages/images-image_popup-r7_fertilization.jpg
1.) Implantation is the time the zygote is made up of 500 cells, and is known as a blastocyst.
2.) Third week
3.) This is significant, because by the end of this week, you are able to tell if you are pregnant by a test.
4.) http://www.aapsj.org/articles/aapsj0802/aapsj080250/aapsj080250_figure4.jpg
1.) When the embryonic period begins, the baby’s brain, spinal cord, heart, and other organs begin to form.
2.) Fourth week
3.) This is significant because without the healthy development of these organs, the child could have problems throughout their entire lives.
4.) http://www.nonprofitpages.com/mcfl/Early.jpeg
1.) The baby’s heart will begin to beat, and the circulatory system is taking shape, and can be detected with an ultrasound.
2.) Fifth week
3.) This is significant because the heart is the most important organ, and needs to constantly checked (ultrasounds can help with this)
4.) http://health.yahoo.com/media/mayoclinic/images/slideshow/pr22_4chamber.jpg
1.) The neural tubes in a baby’s back are now closed, and a baby’s heart is beating with a regular rhythm.
2.) Sixth week
3.) This is significant because growth is one of the most rapid during this week of development.
4.) http://embryology.med.unsw.edu.au/Notes/images/neuron/image_002.gif
1.) The umbilical cord is the link between the baby and the placenta.
2.) Week 7
3.) This is important because this is when the baby is able to receive nutrients from the mother’s food and drinks.
1.) Baby’s fingers and toes start to form, wrists, elbows, and ankles are visible, and the baby’s eyelids are starting to form.
2.) Week 8
3.) This is important because the baby’s limbs are starting to forms
1.) Movement begins, and the embryonic tail at the bottom of the baby’s spinal cord is shrinking, and making them look more human.
2.) Week 9
3.) This is important because the baby can now connect with its mother by moving.
1.) Neurons multiply, and the baby’s vital organs have a solid foundation.
2.) Week 10
3.) This is important because the baby’s ears can start to form, and tooth buds are forming as well.
1.) A baby’s sex may be apparent, and its weight with multiply by thirty, and its length will triple.
2.) Week 11This is important because it is considered the “halfway” mark of conception, and the baby is now officially called a fetus.
Compendium Review #2 (Unit IV)
Human landscapes:
There are several theories of the development of human kind. Two of the most popular theories are that God created everything, and the people evolved into what they are today, in the theory of evolution. However humans were created, we are able to interact with many things in our environment. According to Professor Frolich, in a community, relationships among species can be beneficial, damaging, or neutral.
There are five different types of relationships including symbiotic, parasitic, commensal, mutualism, and predation. Symbiotic simply means that both organisms benefit from interaction (Frolich). Another type of relationship is parasitic, which one species that is the parasite benefits, and the other species known as the host is harmed (Frolich). An addition type of relationship is commensal, which one species directly benefits, but instead of the other being harmed, the species is neutral and isn’t harmed or benefited (Frolich). The fourth type of relationship, known as mutualism, is where both species benefit, similar to symbiosis, but it may appear that one species has the advantage (Frolich). Though this is true, over a long-term period, both species actually benefit (Frolich). Lastly, predation (sometimes considered parasitic), where the predator is the parasite, but can also be seen as mutualistic (Frolich).
Deep time evolutionary history:
According to Professor Frolich, in order to understand evolution, we need to have an appreciation for deep time – time stretching beyond what is easy to intuitively grasp. Deep time is the concept of geologic time which was first recognized in the 1700’s in the western world by Scottish geologist James Hutton (Mader). Science in succeeding centuries has established the age of the Earth as between four and five billion years, with an exceedingly long history of change and development (Unknown).
There has been solid evidence that living humans form one single species known as homo sapiens (Frolich). Homo sapiens have the ability to interbreed, they have a little anatomical difference among populations, and little biochemical difference among populations (Frolich). They also have DNA and protein analysis that show recent single common ancestors within 1 million years.
There are several theories of the development of human kind. Two of the most popular theories are that God created everything, and the people evolved into what they are today, in the theory of evolution. However humans were created, we are able to interact with many things in our environment. According to Professor Frolich, in a community, relationships among species can be beneficial, damaging, or neutral.
There are five different types of relationships including symbiotic, parasitic, commensal, mutualism, and predation. Symbiotic simply means that both organisms benefit from interaction (Frolich). Another type of relationship is parasitic, which one species that is the parasite benefits, and the other species known as the host is harmed (Frolich). An addition type of relationship is commensal, which one species directly benefits, but instead of the other being harmed, the species is neutral and isn’t harmed or benefited (Frolich). The fourth type of relationship, known as mutualism, is where both species benefit, similar to symbiosis, but it may appear that one species has the advantage (Frolich). Though this is true, over a long-term period, both species actually benefit (Frolich). Lastly, predation (sometimes considered parasitic), where the predator is the parasite, but can also be seen as mutualistic (Frolich).
Deep time evolutionary history:
According to Professor Frolich, in order to understand evolution, we need to have an appreciation for deep time – time stretching beyond what is easy to intuitively grasp. Deep time is the concept of geologic time which was first recognized in the 1700’s in the western world by Scottish geologist James Hutton (Mader). Science in succeeding centuries has established the age of the Earth as between four and five billion years, with an exceedingly long history of change and development (Unknown).
There has been solid evidence that living humans form one single species known as homo sapiens (Frolich). Homo sapiens have the ability to interbreed, they have a little anatomical difference among populations, and little biochemical difference among populations (Frolich). They also have DNA and protein analysis that show recent single common ancestors within 1 million years.
http://www.scienceclarified.com/images/uesc_06_img0297.jpg
Natural selection:
Natural selection is the process by which favorable traits that are inherited, become more common in successive generations of a population of reproducing organisms (Mader). This also shows that unfavorable traits that are inherited become less common (Mader). Natural selection is basically the “phenotype”, or the characteristic that can be seen (Mader). In natural selection, people with the “phenotype” characteristic are said to be more likely to survive and reproduce than those with less favorable phenotypes. If these phenotypes have a genetic basis, then the genotype associated with the favorable phenotype will increase in frequency in the next generation (Mader).
http://www.niaaa.nih.gov/NR/rdonlyres/709C2B0A-DCBF-4A58-BD6A-C97BFF472375/0/conversion.gif
Over a long period of time, this process can result in adaptations that specialize organisms for particular ecological niches, which may eventually result in the emergence of new species (Mader). The term natural selection was introduced by Charles Darwin in 1859 (Unknown). Surprisingly, the concept of natural selection was originally developed in the absence of a valid theory of inheritance, and Darwin’s writing had nothing to do with modern genetics (Unknown).
Human Ecology:
Human ecology is basically that academic discipline that deals with the relationship between humans and their natural, social and created environments (Unknown). Human ecology investigates how humans and human societies interact with nature and with their environment (Unknown). When it comes to human ecology and the environment, species that live in communities are what humans interact with everyday (Unknown). Biologically, the human ecosystem has the same components known as biophysical resources (Frolich).
http://www.mdk12.org/instruction/curriculum/hsa/biology/images/ecosystem.gif
The change in ecosystems occurs because of natural processes (Unknown 2). The changes can take years of centuries, working so slowly that they are barely noticed (Unknown 2). They have a systematic pattern generated by community assembly, which follows an orderly progression known as ecological succession, another emergent property of ecosystems (Unknown 2). These ecosystems are able to change themselves, and people also change ecosystems. Because humans impact the ecosystem, and the ecosystem impacts humans, they depend on each other for survival.
Domestication:
Domestication refers to the process of taming a population of animals, plants or other species as a whole (Mader). Humans have brought these different populations under their care for many different reasons (Mader). Some of the reasons include to produce food, or valuable commodities such as wool, cotton, or silk (Mader). Other reasons are to use them for various types of work, transportation, or to enjoy as pets or ornamental plants (Mader).
http://www.dogfacts.org/dog-pictures.jpg
Plants are mainly domesticated for aesthetic enjoyment in and around the home are usually called house plants (Mader). Some plants are also domesticated for large-scale food production, generally known as crops (Mader). Also, domesticated animals are used for home companionship, known as pets, while animals domesticated for food or work are called livestock or farm animals (Mader).
http://files.turbosquid.com/Preview/Content_on_3_13_2003_05_10_27/Plant.jpg0E3A553F-8168-49C3-B5FE1C6CF6270646.jpgLarge.jpg
Although the thought of domestication is pretty clear, there is a debate within the scientific community over how the process of domestication works (Mader). Some researchers give credit to natural selection, where mutations outside of human control make some members of a species more compatible to human cultivation or companionship (Mader). Other researchers have shown that carefully controlled selective breeding is responsible for many of the collective changes associated with domestication (Mader).
Citations:
Frolich, Larry. “Human Landscape powerpoint” pg.1-5
Mader, Sylvia. “Human Biology 10th edition”. 2008
Unknown. “Human ecology” http://www.ecotippingpoints.com/
Unknown 2 “Ecosystems” http://www.windows.ucar.edu/tour/link=/earth/ecosystems.html&edu=elem
Compendium Review #1 (Unit IV)
Reproduction:
Reproduction is formally the biological process where individual organisms are produced (Mader). Reproduction is a fundamental feature of all life, and each individual exits as the result of reproduction (Mader). There are two main types of reproduction known as sexual and asexual (Mader). An individual organism can reproduce by itself without another organism of that species help (Mader). This type of reproduction is found in bacteria, and most plants (Mader). The division of bacterial cells into two daughter cells is an example of asexual reproduction (Mader). Asexual reproduction is also not limited to single-celled organisms (Mader). The opposite is sexual reproduction, which does require the involvement of two individuals (Mader). Normal human reproduction is a common example of sexual reproduction (Mader).
http://static.howstuffworks.com/gif/human-reproduction-female.gif
Human life cycle:
Different researchers studying human development have different perspectives of how many stages in life there are. The human life cycle is said to be briefly broken down into four main stages known as infancy, childhood, adolescence, and adulthood. Infancy is the stage of life that is from birth to the age of two (Unknown). This is the age that children learn to use their gross motor skills, such as walking, as well as the time teeth and language develop rapidly (Unknown). This stage is also where you find disproportions of children’s head and body (Unknown).
http://cache.eb.com/eb/image?id=93125&rendTypeId=4
The next stage is focused on childhood and lasts from two years old to adolescence (Unknown). This is when bones are teeth are growing rapidly, and the time when permanent teeth develop (Unknown). Intellectual skills starts to broaden and become more defined (Unknown).
http://www.thecards.com/images/bigcards/childhood.jpg
The next stage is focused on adolescence, where the body becomes sexually mature (Unknown). Things that can start to occur during the adolescent stage are changes in growth, physically and mentally, and also voice changes for males. Because girls bodies are undergoing puberty (a time where they can become pregnant), they gain extra weight, in order to compensate for having a child (Unknown). This is the time where there are many raging hormones at work, and because the body is undergoing so many changes, it can be a stressful time for teenagers (Unknown).
The last stage for during the human life cycle is adulthood (Unknown). Adulthood is the time when the body slows down the production of all the necessary hormones, and the body is fully grown by this time (Unknown). Life styles changes may occur in adults, such as a decrease in physical activity because of the aging of the body’s joints (Unknown). However, this decrease in physical activity doesn’t have to occur in the adult stages of life, and if children are active and continue to stay healthy throughout their lives, they will age much better than adults that are healthy (Unknown).
Meiosis:
Meiosis, in terms of biology, is the process by which a diploid eukaryotic cell divides in order to generate four haploid cells called gametes (Mader). These gametes are the “sex cells” of the body (Mader). The term meiosis comes from the Greek word meioun, which translates “to make smaller”. This term is used because meiosis is the result in a reduction in chromosomes in the gamete cell (Mader).
http://www.ksu.edu/biology/pob/genetics/meiosis.gif
Meiosis is incredibly important to human beings because is essential for sexual reproduction, and without it, there wouldn’t be sustained life on this earth. Meiosis occurs in all eukaryotes that reproduce sexually, even in less complicated single-celled organisms (Mader). Even though sexual reproduction can occur in all eukaryotes, some have lost the ability to carry out meiosis, and have acquired the ability to reproduce by parthenogenesis (Mader).
During meiosis, the genome of a diploid germ cell, composed of DNA, undergoes DNA replication (Mader). After the DNA is replicated, it is able to be divided, which results in the form of gametes (Mader). Each gamete contains a complete set of chromosomes, or half of the genetic content of the original cell (Mader). This is why two parents genetic content combines to give us offspring that has characteristics of both its genetic donors. The gametes have to fuse together with another gamete of the opposite sex during fertilization, in order to create a new diploid cell, known as a zygote (Mader).
After this fertilization occurs, the division mechanism of meiosis is a reciprocal process to the joining of the two genomes (Mader). The chromosomes of each parent undergo genetic recombination, and each gamete and zygote will have a unique genetic blueprint encoded in its DNA. There are many other features that are unique to meiosis, including pairing and genetic recombination between homologous chromosomes, which means that they share the same origin but have a different function (Mader).
Another thing that occurs during meiosis are several processes including prophase, metaphase, anaphase, and telophase (Mader). In the first stage of prophase, individual chromosomes begin to condense into longs strands within the nucleus (Mader). However, the two sister chromatids are still bond together so tightly that they are indistinguishable from one another (Mader). The next stage during meiosis is metaphase (Mader). During this stage, homologous pairs move together along the phase plate (Mader). The physical basis of the independent assortment of chromosomes is the random orientation of each bivalent along the metaphase plate (Mader). The next stage during meiosis is anaphase (Mader). During this stage the cell elongates in preparation for division down the middle. Also, homologous chromosomes that are closely associated in synapsis exchange segments by crossing over. The last stage during meiosis is telophase (Mader). During this stage, the microtubules that make up the spindle network disappear, and a new nuclear membrane surrounds each haploid set. The chromosomes uncoil back into chromatin. After that, cytokinesis (the pinching of the cell membrane) occurs, which completes the process of creating two daughter cells (Mader).
Fetal development and birth:
In early fetal development, there are three main stages a fetus goes through. These stages include the Germinal Stage, the Embryonic Stage, and the Fetal Stage (Feldman pg 75). The Germinal stage occurs from fertilization to two weeks of age. This is the shortest stage of prenatal development, but important because this is when the placenta is able to be used for nutrients and waste disposal through the umbilical cord (Feldman pg 74). The Embryonic stage occurs two weeks to eight weeks following fertilization (Feldman pg 75). This is the most important stage because the entire development of a child occurs during this stage (Feldman pg 75).
http://www.orwelltoday.com/babyub.jpg
There are three layers that form a different set of structures as a child’s development proceeds (Feldman pg 75). These layers are called the ectoderm, endoderm, and mesoderm. The ectoderm is where skin, hair, teeth, sense organs, the brain, and spinal cord will develop (Feldman pg 75). The endoderm produces the digestive system, liver, pancreas, and respiratory system (Feldman pg 75). Lastly, the mesoderm is where the muscles, bones, blood, and circulatory system are formed (Feldman pg 75). The last stage in fetal development is the fetal stage. This occurs from eight weeks until birth. Now the child is considered a fetus, and this is where labor comes into play (Feldman pg 75).
During all of these stages genes and chromosomes will be passed down to a child, and different aspects of their life are inherited (Feldman pg 125). Genes are what makes us look, and where different aspects of our behavior come from (Feldman pg 125). Chromosomes also play a very important role, and without even just one of them could cause several problems. For example, Fragile X syndrome occurs when a particular gene is injured on the X chromosome, which results in mild to moderate mental retardation (Feldman pg 56). Down syndrome can also occur when the presence of an extra chromosome is on the 21st pair. Another disorder is Klinefelter’s syndrome. Klinefelter’s syndrome occurs when there is the presence of an extra X chromosome, which accounts for genetic ‘gender’ related abnormalities (Feldman pg 56). These abnormalities occur from receiving the improper number of sex chromosomes (Feldman pg 56). In conclusion, having the correct amount of chromosomes and properly working genes can mean a huge difference in people’s lives.
Citations:
Mader, Sylvia. Human Biology 10th edition. 2008
Feldman, Robert. Development across the life span 4th edition 2006.
Unknown. “Human life cycle” http://***.tqnyc.org/NYC040719/life_cycle.htm
Sunday, July 15, 2007
Ethical issues essay #3
Exercise--is the concept working?
All you have to do is eat healthy and exercise. Sounds like a simple concept, right? Wrong! These things can seem like very simple concepts, but can be very difficult for many people. There are many obstacles that can force someone into an unhealthy, and no time for exercise. School is a very good example. Although most college age students are relatively healthy, this isn’t due to their diet and profound exercise. Our bodies are able to regulate our unhealthy habits while we are young, but can have horrible results in the future. When it comes to exercise, time and energy are important factors in being able to do physical activity. Most people may not have the money to get a gym membership, or a car to get to the gym, or simply just no time or lack of energy due to the many stressful things that overwhelm human life. I don’t know if the concept of exercise is actually working. Seeing that a large percentage of people in our country are overweight, or obese, it is clear that we either don’t have time to exercise and eat right, or people are just to lazy to take care of themselves. Either way it is becoming an increasing problem, and is going to keep negatively effecting our world, until we can find a better alternative. According to the World Heath Organization, they predict that by the year 2050, 75% of all deaths will be caused by overweight related diseases and cancers. This number is outrageous, and something needs to be done in order to save millions of lives. People need to work together to incorporate more exercise programs, starting from grade school and up. Grade school children will be able to incorporate exercise, and continue a healthy lifestyle if they learn right away. The best way to do this is to make physical activity a requirement in the school system. Even in college, stressed out college students could be lacking in their health due to focusing on studies, but if a yoga or pilates class was required, maybe there would be more physically fit people.
All you have to do is eat healthy and exercise. Sounds like a simple concept, right? Wrong! These things can seem like very simple concepts, but can be very difficult for many people. There are many obstacles that can force someone into an unhealthy, and no time for exercise. School is a very good example. Although most college age students are relatively healthy, this isn’t due to their diet and profound exercise. Our bodies are able to regulate our unhealthy habits while we are young, but can have horrible results in the future. When it comes to exercise, time and energy are important factors in being able to do physical activity. Most people may not have the money to get a gym membership, or a car to get to the gym, or simply just no time or lack of energy due to the many stressful things that overwhelm human life. I don’t know if the concept of exercise is actually working. Seeing that a large percentage of people in our country are overweight, or obese, it is clear that we either don’t have time to exercise and eat right, or people are just to lazy to take care of themselves. Either way it is becoming an increasing problem, and is going to keep negatively effecting our world, until we can find a better alternative. According to the World Heath Organization, they predict that by the year 2050, 75% of all deaths will be caused by overweight related diseases and cancers. This number is outrageous, and something needs to be done in order to save millions of lives. People need to work together to incorporate more exercise programs, starting from grade school and up. Grade school children will be able to incorporate exercise, and continue a healthy lifestyle if they learn right away. The best way to do this is to make physical activity a requirement in the school system. Even in college, stressed out college students could be lacking in their health due to focusing on studies, but if a yoga or pilates class was required, maybe there would be more physically fit people.
Saturday, July 14, 2007
Compendium review #2 (Unit III)
Movement:
In order for humans to move about the world, they first need muscle cells (Suny). Muscle cells are specialized for contractility, and can be classified according to their microscopic appearance (Suny). They can also be sorted into three major categories including smooth muscle, skeletal muscle and cardiac muscle (Suny). Smooth muscle is usually found in tubular organs, where as skeletal muscle is usually attached to bones (Suny). Lastly, cardiac muscle is usually found in the wall of the heart (Suny).
In order for humans to move about the world, they first need muscle cells (Suny). Muscle cells are specialized for contractility, and can be classified according to their microscopic appearance (Suny). They can also be sorted into three major categories including smooth muscle, skeletal muscle and cardiac muscle (Suny). Smooth muscle is usually found in tubular organs, where as skeletal muscle is usually attached to bones (Suny). Lastly, cardiac muscle is usually found in the wall of the heart (Suny).
http://www.cytochemistry.net/microanatomy/muscle/smooth1.jpg
The smooth muscle cell is spindle-shaped, and has an elongated nucleus that is in the middle of the cell (Suny). Smooth muscle cells may occur as solitary fibers such as those found in the spleen capsule, or grouped together in bundles known as fascicles (Suny). These fascicles can be isolated, or can be in sheets around tubular organs or vessels (Suny). Blood vessels can also be found between these fascicles (Suny).
There are also the skeletal muscle, that are unlike the smooth muscle cell, and do not have one nucleus, but many nuclei (Suny). This nuclei is also not located in the center of the cell, but rather the periphery of the cell, located just under the sarcolemma (Suny). The fiber of this cell is also filled with parallel myofibrils, which extend the length of the cell (Suny). The cross-banding of the adjacent myofibrils are then aligned with each other so the banding is able to be seen across the whole fiber (Suny).
Lastly, the cardiac muscle found around the heart, are equally important (Suny). The longitudinal sections of cardiac fibers, make it so the myofibrils can be seen by the branching of the fibers (Suny). Like the smooth muscle, the nuclei is located centrally. Also like the skeletal muscle, there are several nuclei, not just one as in the smooth muscle (Suny).
http://www.besthealth.com/besthealth/bodyguide/reftext/images/100085.jpg
Muscle cells, contraction and calcium:
In order for humans to move and use their limbs for complex activities, we must first look at muscle contraction. Muscle contraction occurs when a muscles cell lengthens or shortens (Mader). The process of locomotion, found in more complex animals, is possible only through the repeated contraction of many muscles at certain times (Mader). Contraction is actually controlled by the central nervous system, which is comprised of mostly the brain and spinal cord (Mader). The brain is what controls voluntary muscles contractions, while the spinal cord controls involuntary reflexes (Mader).
Muscle cells, contraction and calcium:
In order for humans to move and use their limbs for complex activities, we must first look at muscle contraction. Muscle contraction occurs when a muscles cell lengthens or shortens (Mader). The process of locomotion, found in more complex animals, is possible only through the repeated contraction of many muscles at certain times (Mader). Contraction is actually controlled by the central nervous system, which is comprised of mostly the brain and spinal cord (Mader). The brain is what controls voluntary muscles contractions, while the spinal cord controls involuntary reflexes (Mader).
http://www.bodytrends.com/articles/strength/images/musclefail_100x136.jpgThe term contraction actually implies that something is being shortened or reduced in the muscular system, and refers to the generation of force by muscle fibers (Mader). During muscular contraction, a muscle’s length can decrease, increase or remain constant (Mader). There are two main types of contraction of muscles: concentric, and eccentric (Mader). Concentric contraction is a a type of muscle contraction where the muscles shorten while generating force (Mader). During this type of contraction, a muscle is stimulated to contract according to the sliding filament mechanism (Mader). This actually occurs throughout the length of the muscle, which generates force at the musculo-tendinous junction (Mader). This causes the muscle to shorten and change the angle of the joint, making us able to move (Mader). If we used the elbow joint as an example, a concentric contraction of the biceps would cause the arm to bend at the elbow, and the hand to move from the leg close to the shoulder, known as a bicep curl (Mader).
In eccentric contraction, the force opposing the contraction of the muscle is actually greater than the force produced by the muscle (Mader). Instead of working to pull a joint in the direction of the muscle contraction, the muscle slows the movement of a joint, and lengthens while generating force (Mader). Even though this force is generated by the muscle is less than the force opposing contraction, it may still be below the maximal force to muscle the muscle could potentially produce (Mader). Again, using the example of the elbow joint, in relation to the arm, an eccentric contraction of the biceps muscle, the elbow would straighten and a hand would move from the shoulder to thigh (Mader). Muscles are more likely to undergo heavy eccentric loading is it is suffering from greater damage (Mader). In other words, if you do too much exercise, you will exert an overload of strain on your body, which makes your muscles soar and tired (Mader).
Movement across joints:
When it comes to joints, most of them can be considered freely movable joints (Frolich). The joints consist of the joint capsule, articular cartilage, synovial membrane, and synovial (joint) cavity (Mader). There aer also six classification of freely movable joints: ball in-socket, condyloid, gliding, hinge, pivot, and saddle (Mader). These joints are said to be more complex structures than immovable and slightly movable joints (Mader). In these types of joints, the end of the bones are covered with a smooth layer of cartilage, and the whole joint is enclosed in a watertight membrane that contains a small amount of lubricating fluid (Mader). This lubrication is very important, because it allows the joint to work with little friction (Mader).
When it comes to joint movement, there are four main types: gliding, angular, rotation, and circumduction. Gliding is the simplest of these motions, and moves without using any rotary or angular motion (Mader). This motion only exists between two adjacent surfaces (Mader). The next type if angular motion (Mader). Angular motion decreases or increases the angle between two adjoining bones (Mader). The most common types of angular motion are flexion, bending arm or leg, extension, straightening or unbending, abduction, and moving an extremity toward the body (Mader). The next type of joint movement is rotation (Mader). Rotation is a movement in which the bone moves around a central point without being displaces, such as turning your head from side to side (Mader).
http://www.eorthopod.com/images/ContentImages/elbow/elbow_arthroplasty/elbow_arthro_anatomy01.jpgBones, bone tissue, and calcium:
Bone tissue, also known as osseous tissue, is the major structural and supportive connective tissue of the body (Mader). Osseous tissue forms in the rigid part of the bone organs which make up the skeletal system (Mader). This type of bone tissue is a mineralized connective tissue (Mader). Bone-forming cells called osteoblasts deposit a matrix of collagen, but also release calcium, magnesium, and phosphate ions (Mader). All of these things chemically combine and harden within the matrix (Mader). This combination of hard mineral and flexible collagen makes bone harder than cartilage without being brittle (Mader).
There are two main types of osseous tisse: compact, and spongy (Mader). Compact bone forms the extremely hard exterior while spongy bonds fills the hollow interior (Mader). The tissues are biologically identical, and the difference is in how the microstructure is arranged (Mader).
Osseous tissue is important is performing numerous functions such as support for muscles, organs, and soft tissues (Mader). This tissue is also used for leverage and movement, and used to protect vital organs such as the heart (Mader). Osseous tissue is also important for calcium phosphate storage (Mader).
http://www.unm.edu/~jimmy/long_bone.jpgBones are different than bone tissue (Mader). Bones are organs that are made up of bone tissue, as well as marrow, blood vessels, epithelium, and nerves (Mader). Bone tissues is only the mineral matrix that form the rigid sections of the organ (Mader).
Citations:
Frolich, Larry. “Nervous Function Powerpoint” pg. 3-7
Mader, Robert. “Human Biology 10th ed”. 2008.
Suny Downstate Medical Center. “Muscle” http://ect.downstate.edu/courseware/histomanual/muscle.html
Compendium review #1 (Unit III)
Neurons:
There are two main types of neurons in the body (Mader).
These include motor and sensory neurons (Mader). Motor neurons are located in the Central Nervous System of the body, and either directly or indirectly control muscles. When this occurs, their axons are actually projected outside the central nervous system. This type of neuron is responsible for many types of muscle control, which involves movement of all limbs (Mader). Each motor neuron is also responsible for many organs as well as muscles (Mader).
http://cache.eb.com/eb/image?id=72120&rendTypeId=35
Sensory neurons are just as important as motor neurons. Sensory neurons are nerve cells that are located in the nervous system. These neurons are responsible for converting external stimuli from an organism’s environment into an internal electrical motor reflex (Frolich). This reflex loops, and makes several forms of involuntary behavior form, including pain avoidance (Mader). These neurons can be found in animals, but in most humans these reflex circuits are usually found in the spinal cord (Mader).
In complex organisms, sensory neurons relay their information to the central nervous system (Mader). In less complex organisms, sensory neurons transmit information to the brain where it can be further processed (Mader). When it comes to olfactory sensory neurons (neurons involved in smell), these neurons make synapses with neurons of the olfactory bulb, and the sense of smell is processed (Mader). 
http://www.mind.ilstu.edu/curriculum/neurons_intro/imgs/neuron_types.gif
Molecularly, sensory receptors can be found on the cell membrane of sensory neurons (Mader). These neurons are responsible for the conversion of stimuli into important electrical impulses (Mader). The type of receptor employed by a given sensory neuron is what determines the type of stimuli that it will be sensitive to (Mader). Going back to the sensory receptors for smell, the olfactory receptors make a cell sensitive to odors, and make it so humans can have this sense (Mader).
http://www.nature.com/embor/journal/v3/n4/images/embor178-f2.jpg
Nervous system function:
The nervous system is extremely important in all living things, and is the major controlling, regulatory, and communicating system in the body (Unknown). It is also the center of all mental activity (Unknown). These activities include everything from thought, to learning and memory (Unknown). The nervous system, combined with the endocrine system are responsible for regulating and maintaining the body’s much needed homeostasis, in order to keep it regular (Unknown). The nervous system is also to keep us in touch with our environment, externally and internally by the action of its receptors (Unknown). The nervous system is similar to that of other systems in the body, because it is composed of organs (Unknown). The main parts that make up the nervous system are the brain, spinal cord, nerves, and the ganglia (Unknown). This system also includes various tissues, including nerve, connective, and blood tissue (Unknown). All of these organs and tissues together carry out the complex activities of the nervous system.
http://www.ama-assn.org/ama1/pub/upload/images/446/nervousatlasgroups.gif
The nervous system can be generalized into three categories of activity (Unknown) . These categories include sensory, integrative, and motor (Unknown). Along with these categories, come millions of sensory receptors that detect changes inside and outside of the body, known as stimuli. They receptors watch for things such as temperature, light, and sound from our environment (Unknown) . They also detect things in the internal environment such as variations in pressure, pH, and carbon dioxide concentration (Unknown). All of this information together is known as sensory input (Unknown). This type of input is converted into electrical signals, known as nerve impulses, and are transmitted to the brain. These impulses create signals that are brought together in order to create sensations or produce thought (Unknown).
Diffusion and Action:
The electrical discharge that travels along the membrane of a cell occurs because of action potential (Mader). Action potentials are essential, especially in human and animal life, because they rapidly carry information with and between tissues (Mader). Action potentials can be created by many types of cells, but are commonly used by the nervous system for communication between neurons (Mader). Action potentials can also transmit information from neurons to other body tissues such as muscles and glands (Mader). This is extremely important in make our body function as a whole, and make parts of our body move, and understand our internal world (Mader).
http://www.getbodysmart.com/ap/nervoussystem/neurophysiology/actionpotentials/menu/image.gif
Although action potentials can be in different cells of animals, some plants, and humans, they are not the same in all cell types (Frolich). Action potential can even vary in their properties at different locations, even if they are in the same cell (Frolich). Cardiac action potentials are an example of this, and are significantly different from the action potentials in most neurons (Frolich). Action potentials are so important to human life, because they give us many different abilities we use in everyday life. For example, action potentials give us the ability to sense our environment, and process informaion rapidly and respond to the rapid transmission of messages within the body (Frolich). Action potentials are also responsible for transmitting messages that are unique to animals (Frolich).
Reflex arc:
A reflex arc is known as the neural pathway which mediates a reflex action (Mader). This means that in more complex animals, most of the sensory neurons don’t pass directly into the brain, but through a synapse in the spinal cord (Mader). A reflex action is able to occur because of this characteristic, which occurs relatively quickly, and activates the spinal motor neurons (Mader). This process is able to go faster because there is no delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs (Mader).
http://www.merck.com/media/mmhe2/figures/fg077_1.gif
There is also a somatic reflex arc (Unknown 2). This is the simplest possible arrangement of elements to permit a response to stimuli, and the final element in the chain is skeletal muscle (Unknown 2). This system includes sensory transducers in the periphery, such as Pacinian corpuscles and other tactile sensors in the skin (Unknown 2). Also included in this system is the pseudounipolar sensory neuron, interconnector neurons, and the effector organ (Uknown 2).
http://education.vetmed.vt.edu/Curriculum/VM8054/Labs/Lab9/IMAGES/DRAW05.JPG
What can we sense?:
All over our bodies we have sensory receptors that enable us to respond to stimulus from our body internally, or externally through our environment (Frolich). These receptor cells also trigger action potential in connecting sensory neurons (Frolich). Even though we have these receptors all over our body, the majority are in the spinal cord and brain, and are responsible for interpreting and analyzing information (Frolich). They are able to analyze the questions, where, what, how much, and how strong (Frolich).
All of these examples are unconscious processes that all normal bodies undergo (Frolich). Although this is true, there are somatic sensory perceptions that are conscious (Frolich). These perceptions occur in large fields of the brain, and are responsible for organizing information spatially (Frolich). In perceptions that are visual, the visual cortex is responsible for forming a visual field, or complete visual image for humans to see (Frolich).
Sensory cortex maps for touching sensations all over the surface of our skin are also very important (Frolich). If we didn’t have cutaneous receptors on our skin, we wouldn’t be able to touch, feel pressure, tell the difference between hot and cold objects, or feel pain (Frolich). Ultimately these receptors are responsible for making humans feel alive.
http://thebrain.mcgill.ca/flash/i/i_06/i_06_cr/i_06_cr_mou/i_06_cr_mou_1b.jpg
Many people also forget that we have many more than just five senses. We have other senses that are not as obvious, such as the sense of proprioception (Frolich). This is what gives our body position by sensing muscle tension (Frolich). Without this, we wouldn’t be able to tell if our bodies are sitting, or standing (Frolich). Another important sense that we don’t think about it, is equilibrium (Frolich). This is probably the most important of our senses, and gives us the able to stand up straight, and have balance (Frolich). Without this quality, we wouldn’t be able to move any parts of our body without falling, and would never be able to do virtually nothing (Frolich).
http://cache.eb.com/eb/image?id=14304&rendTypeId=4
Citations:
Frolich, Larry. “Nervous Function Powerpoint” pg. 3-7
Mader, Robert. “Human Biology 10th ed”. 2008.
Unknown “Functions of the nervous system”. 2007. http://training.seer.cancer.gov/module_anatomy/unit5_1_nerve_functions.html
Unknown 2 “Somatic reflex arc”. 2007. http://education.vetmed.vt.edu/Curriculum/VM8054/Labs/Lab9/Examples/exsomarc.htm
There are two main types of neurons in the body (Mader).
These include motor and sensory neurons (Mader). Motor neurons are located in the Central Nervous System of the body, and either directly or indirectly control muscles. When this occurs, their axons are actually projected outside the central nervous system. This type of neuron is responsible for many types of muscle control, which involves movement of all limbs (Mader). Each motor neuron is also responsible for many organs as well as muscles (Mader).
http://cache.eb.com/eb/image?id=72120&rendTypeId=35
Sensory neurons are just as important as motor neurons. Sensory neurons are nerve cells that are located in the nervous system. These neurons are responsible for converting external stimuli from an organism’s environment into an internal electrical motor reflex (Frolich). This reflex loops, and makes several forms of involuntary behavior form, including pain avoidance (Mader). These neurons can be found in animals, but in most humans these reflex circuits are usually found in the spinal cord (Mader).
In complex organisms, sensory neurons relay their information to the central nervous system (Mader). In less complex organisms, sensory neurons transmit information to the brain where it can be further processed (Mader). When it comes to olfactory sensory neurons (neurons involved in smell), these neurons make synapses with neurons of the olfactory bulb, and the sense of smell is processed (Mader). http://www.mind.ilstu.edu/curriculum/neurons_intro/imgs/neuron_types.gif
Molecularly, sensory receptors can be found on the cell membrane of sensory neurons (Mader). These neurons are responsible for the conversion of stimuli into important electrical impulses (Mader). The type of receptor employed by a given sensory neuron is what determines the type of stimuli that it will be sensitive to (Mader). Going back to the sensory receptors for smell, the olfactory receptors make a cell sensitive to odors, and make it so humans can have this sense (Mader).
http://www.nature.com/embor/journal/v3/n4/images/embor178-f2.jpg
Nervous system function:
The nervous system is extremely important in all living things, and is the major controlling, regulatory, and communicating system in the body (Unknown). It is also the center of all mental activity (Unknown). These activities include everything from thought, to learning and memory (Unknown). The nervous system, combined with the endocrine system are responsible for regulating and maintaining the body’s much needed homeostasis, in order to keep it regular (Unknown). The nervous system is also to keep us in touch with our environment, externally and internally by the action of its receptors (Unknown). The nervous system is similar to that of other systems in the body, because it is composed of organs (Unknown). The main parts that make up the nervous system are the brain, spinal cord, nerves, and the ganglia (Unknown). This system also includes various tissues, including nerve, connective, and blood tissue (Unknown). All of these organs and tissues together carry out the complex activities of the nervous system.
http://www.ama-assn.org/ama1/pub/upload/images/446/nervousatlasgroups.gif
The nervous system can be generalized into three categories of activity (Unknown) . These categories include sensory, integrative, and motor (Unknown). Along with these categories, come millions of sensory receptors that detect changes inside and outside of the body, known as stimuli. They receptors watch for things such as temperature, light, and sound from our environment (Unknown) . They also detect things in the internal environment such as variations in pressure, pH, and carbon dioxide concentration (Unknown). All of this information together is known as sensory input (Unknown). This type of input is converted into electrical signals, known as nerve impulses, and are transmitted to the brain. These impulses create signals that are brought together in order to create sensations or produce thought (Unknown).
Diffusion and Action:
The electrical discharge that travels along the membrane of a cell occurs because of action potential (Mader). Action potentials are essential, especially in human and animal life, because they rapidly carry information with and between tissues (Mader). Action potentials can be created by many types of cells, but are commonly used by the nervous system for communication between neurons (Mader). Action potentials can also transmit information from neurons to other body tissues such as muscles and glands (Mader). This is extremely important in make our body function as a whole, and make parts of our body move, and understand our internal world (Mader).
http://www.getbodysmart.com/ap/nervoussystem/neurophysiology/actionpotentials/menu/image.gif
Although action potentials can be in different cells of animals, some plants, and humans, they are not the same in all cell types (Frolich). Action potential can even vary in their properties at different locations, even if they are in the same cell (Frolich). Cardiac action potentials are an example of this, and are significantly different from the action potentials in most neurons (Frolich). Action potentials are so important to human life, because they give us many different abilities we use in everyday life. For example, action potentials give us the ability to sense our environment, and process informaion rapidly and respond to the rapid transmission of messages within the body (Frolich). Action potentials are also responsible for transmitting messages that are unique to animals (Frolich).
Reflex arc:
A reflex arc is known as the neural pathway which mediates a reflex action (Mader). This means that in more complex animals, most of the sensory neurons don’t pass directly into the brain, but through a synapse in the spinal cord (Mader). A reflex action is able to occur because of this characteristic, which occurs relatively quickly, and activates the spinal motor neurons (Mader). This process is able to go faster because there is no delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs (Mader).
http://www.merck.com/media/mmhe2/figures/fg077_1.gif
There is also a somatic reflex arc (Unknown 2). This is the simplest possible arrangement of elements to permit a response to stimuli, and the final element in the chain is skeletal muscle (Unknown 2). This system includes sensory transducers in the periphery, such as Pacinian corpuscles and other tactile sensors in the skin (Unknown 2). Also included in this system is the pseudounipolar sensory neuron, interconnector neurons, and the effector organ (Uknown 2).
http://education.vetmed.vt.edu/Curriculum/VM8054/Labs/Lab9/IMAGES/DRAW05.JPG
What can we sense?:
All over our bodies we have sensory receptors that enable us to respond to stimulus from our body internally, or externally through our environment (Frolich). These receptor cells also trigger action potential in connecting sensory neurons (Frolich). Even though we have these receptors all over our body, the majority are in the spinal cord and brain, and are responsible for interpreting and analyzing information (Frolich). They are able to analyze the questions, where, what, how much, and how strong (Frolich).
All of these examples are unconscious processes that all normal bodies undergo (Frolich). Although this is true, there are somatic sensory perceptions that are conscious (Frolich). These perceptions occur in large fields of the brain, and are responsible for organizing information spatially (Frolich). In perceptions that are visual, the visual cortex is responsible for forming a visual field, or complete visual image for humans to see (Frolich).
Sensory cortex maps for touching sensations all over the surface of our skin are also very important (Frolich). If we didn’t have cutaneous receptors on our skin, we wouldn’t be able to touch, feel pressure, tell the difference between hot and cold objects, or feel pain (Frolich). Ultimately these receptors are responsible for making humans feel alive.
http://thebrain.mcgill.ca/flash/i/i_06/i_06_cr/i_06_cr_mou/i_06_cr_mou_1b.jpg
Many people also forget that we have many more than just five senses. We have other senses that are not as obvious, such as the sense of proprioception (Frolich). This is what gives our body position by sensing muscle tension (Frolich). Without this, we wouldn’t be able to tell if our bodies are sitting, or standing (Frolich). Another important sense that we don’t think about it, is equilibrium (Frolich). This is probably the most important of our senses, and gives us the able to stand up straight, and have balance (Frolich). Without this quality, we wouldn’t be able to move any parts of our body without falling, and would never be able to do virtually nothing (Frolich).
http://cache.eb.com/eb/image?id=14304&rendTypeId=4
Citations:
Frolich, Larry. “Nervous Function Powerpoint” pg. 3-7
Mader, Robert. “Human Biology 10th ed”. 2008.
Unknown “Functions of the nervous system”. 2007. http://training.seer.cancer.gov/module_anatomy/unit5_1_nerve_functions.html
Unknown 2 “Somatic reflex arc”. 2007. http://education.vetmed.vt.edu/Curriculum/VM8054/Labs/Lab9/Examples/exsomarc.htm
Online Activity #2 (Unit III)
Figure 1: Effect of Temperature on Muscle Action
Temperature
Number of Fists
Normal
---------------35
Ice Water
---------------16
Effect of Fatigue on Muscle Action
1. Count how many times you can tightly squeeze a rubber ball in your hand
in 20 seconds. Record in Figure 2.
2. Repeat the squeezing nine more times and record results. Do not rest
between trials.
(An alternative procedure which works well is to open and close a
clothespin with the thumb and index finger while the other fingers are held
out straight.)
Figure 2: Effect of Fatigue on muscle action
Trial
# of Squeezes in 20 seconds
9 More X's
1
15
10
2
14
10
3
14
10
4
13
8
5
14
8
6
11
8
7
12
9
8
12
7
9
13
8
10
12
6
ANALYSIS OF DATA:
1. What are the three changes you observed in a muscle while it is working (contracted)?
The muscle became harder to move, it became really hard to make a fist time after time, and also slowed reaction time.
2. What effect did the cold temperature have on the action of your hand muscles? Explain.
It made the muscles contract slower, and make my hand close slower, and not be able to close as tight.
3. In Figure 3, make a line graph of your results of the fatigue experiment. Be sure to fill in the values on the vertical axis.
Figure 3: Graph of Effect of Fatigue on Muscle Action
Attempts Number
4. What effect did fatigue have on the action of your hand muscles? Explain.
Fatigue had a huge effect on my hand muscles because it made my reaction time slower, and obviously tired out the muscles, which make the ability of making a fist much slower and harder.
Temperature
Number of Fists
Normal
---------------35
Ice Water
---------------16
Effect of Fatigue on Muscle Action
1. Count how many times you can tightly squeeze a rubber ball in your hand
in 20 seconds. Record in Figure 2.
2. Repeat the squeezing nine more times and record results. Do not rest
between trials.
(An alternative procedure which works well is to open and close a
clothespin with the thumb and index finger while the other fingers are held
out straight.)
Figure 2: Effect of Fatigue on muscle action
Trial
# of Squeezes in 20 seconds
9 More X's
1
15
10
2
14
10
3
14
10
4
13
8
5
14
8
6
11
8
7
12
9
8
12
7
9
13
8
10
12
6
ANALYSIS OF DATA:
1. What are the three changes you observed in a muscle while it is working (contracted)?
The muscle became harder to move, it became really hard to make a fist time after time, and also slowed reaction time.
2. What effect did the cold temperature have on the action of your hand muscles? Explain.
It made the muscles contract slower, and make my hand close slower, and not be able to close as tight.
3. In Figure 3, make a line graph of your results of the fatigue experiment. Be sure to fill in the values on the vertical axis.
Figure 3: Graph of Effect of Fatigue on Muscle Action
Attempts Number
4. What effect did fatigue have on the action of your hand muscles? Explain.
Fatigue had a huge effect on my hand muscles because it made my reaction time slower, and obviously tired out the muscles, which make the ability of making a fist much slower and harder.
Online activity #1 (Unit III)
1. What is the electrode measuring?
In this experiment, we used a microelectrode. Electrodes record the activity of neurons in the leech.
2. Why use leeches in neurophysiology experiments?
Although leeches are basic, they give us a good idea of how more complex organisms work. Also, many people don’t have an emotional attachment to leeches, and don’t really mind if they are operated on. 3. What is the difference between a sensory and a motor neuron?
Sensory neurons are nerve cells within in the nervous system that are responsible for converting external stimuli from an organism’s environment. In humans, these are usually located in the spinal cord. Motor neurons are located in the central nervous system, and project their axons outside this system in order to control muscles.
4. Do you think a leech experiences pain? What is pain?
Pain is defined as an unpleasant sensation. I believe that although leeches are simple creatures, they can experience pain, just like most other organisms. I also think that they can experience pain because at the beginning of the experience, we had to put anesthesia in the leech. 5. What were the two most interesting things about doing this lab?
I thought that it was interesting when the dye went into the leech, and you could see everything internally and fluorescent. It was also interesting being able to use all the different tools in order to examine the leech.6. Anything you found confusing or didn't like about the lab?
I don’t like that I can’t even copy the pictures in the labs, but other than that the labs are fine.
Picture descriptions (because I can’t copy the pictures):
The ultraviolet image of the neuron with dye in it showing is has the shape of a sensory neuron. After the leech is cut open, and the dye is injected, and the UV switch is turned on, the outside shape is a green florescent diamond. There are two thin lines that come down from the top, and another line from the middle crossing the top lines. Off of the bottom lines are many more smaller lines, which are the axon and dendrites. In the right hand corner, you can see a bright circle, which is highlighting the neuron.
Now in the oscillope trace readings, I was able to identify a cell by using the probe. I identified that the “P cell” was the correct type in this experiment.
In this experiment, we used a microelectrode. Electrodes record the activity of neurons in the leech.
2. Why use leeches in neurophysiology experiments?
Although leeches are basic, they give us a good idea of how more complex organisms work. Also, many people don’t have an emotional attachment to leeches, and don’t really mind if they are operated on. 3. What is the difference between a sensory and a motor neuron?
Sensory neurons are nerve cells within in the nervous system that are responsible for converting external stimuli from an organism’s environment. In humans, these are usually located in the spinal cord. Motor neurons are located in the central nervous system, and project their axons outside this system in order to control muscles.
4. Do you think a leech experiences pain? What is pain?
Pain is defined as an unpleasant sensation. I believe that although leeches are simple creatures, they can experience pain, just like most other organisms. I also think that they can experience pain because at the beginning of the experience, we had to put anesthesia in the leech. 5. What were the two most interesting things about doing this lab?
I thought that it was interesting when the dye went into the leech, and you could see everything internally and fluorescent. It was also interesting being able to use all the different tools in order to examine the leech.6. Anything you found confusing or didn't like about the lab?
I don’t like that I can’t even copy the pictures in the labs, but other than that the labs are fine.
Picture descriptions (because I can’t copy the pictures):
The ultraviolet image of the neuron with dye in it showing is has the shape of a sensory neuron. After the leech is cut open, and the dye is injected, and the UV switch is turned on, the outside shape is a green florescent diamond. There are two thin lines that come down from the top, and another line from the middle crossing the top lines. Off of the bottom lines are many more smaller lines, which are the axon and dendrites. In the right hand corner, you can see a bright circle, which is highlighting the neuron.
Now in the oscillope trace readings, I was able to identify a cell by using the probe. I identified that the “P cell” was the correct type in this experiment.
Thursday, July 12, 2007
Unit III Lab Project
Introduction:
This model represents a movable, flexible limb. This model also shows the elbow joint, and how it makes the arm move. Neurons and muscle cells are also depicted in this model, as well as their specific function in the arm. The essential elements presented in this model include neurons carrying action potentials that trigger muscle (neurotransmitter), actin-myosin sliding filaments, a bony element that muscle attaches to and moves, and a joint that allows for movement.
The neurons presented in this model include axon with schwann cells, movements of charged sodium and potassium ions across the membrane (action potential), and the propagation of action potential along the axon. There are also several aspects of the muscle cells included in this model, such as sarcolemma and T-tubule membranes, a sarcomere, the release of calcium from the Sarcoplasmic reticulum, calcium binding to myosin, and myosin cross-bridges that bring actin filaments together. All of these things put together make a simple limb movement.
Elbow joint – This joint is considered a hinge joint in the body, in which this joint only moves in one direction. This joint is also formed by three bones; the humerus, radius, and ulna and allows the arm to move.
Neurotransmitters – These chemicals are used in order to amplify and relay electrical signals between a neuron and another cell. Within the cell, small neurotransmitter molecules are usually found in vesicles. When action potential occurs, and travels to the synapse, depolarization causes the calcium ion channels to open, which leads to the process of exocytosis.
Actin-myosin sliding filaments – These filaments are responsible for many types of movement in the muscle. Myosin is the prototype of a protein that converts chemical energy in the form of ATP to mechanical energy, in order to create enough force to make the arm move.
Bony element that muscle attaches to – The two ends of the muscle belly are attached to a bone by a muscle tendon. The bone that remains stable during movement is known as the origin, and the bone that moves when the muscle belly contracts in known as insertion. A muscle can make an arm move when insertion occurs, and moves toward the origin, as the muscle belly shortens.
Axon with Schwann cells – Schwann cells speed up and save energy for the processes of action potentials. This variety of neuroglia mainly provides myelin insulation to axons in the peripheral nervous system of our bodies.
Action potential – This process of electrical discharge is very important in order to carry information within and between tissues. This charge travels along the membrane of a cell, and essential in animal and some plant life.
Propagation of action potential – Propagation is the interaction between membrane depolarization and sodium channels. Action potential will propagate in unmyelinated axons, and let sodium ions enter the cell by facilitated diffusion.
Sarcolemma – This is the cell membrane of a muscle cell which receives and conducts stimuli. This membrane is extendable, and encloses different substances from muscle fiber.
Sarcomere – This is the basic unit of a muscle’s myofibril. Sarcomeres are multi-protein complexes which are composed of three different filament systems. The different bands in the sarcomeres allow muscle contraction to occur, and expand and contract in order make the muscle move.
Release of Calcium – This process is important because it lets ATP hydrolysis occur, which supplies energy in the actin-myosin complex. When the action potential triggers a myocyte to contract, calcium ions are able to enter. This calcium actually triggers the release of more calcium ions that are stored in the sarcoplasmic reticulum.
Calcium binding to myosin – This calcium is then able to bind to myosin, after the energy is supplied in the actin-myosin complex. This is needed in order to trigger a contraction of the muscle.
Myosin cross-bridges – During this cycle, actin combines with myosin, and ATP is used to produce force. This ATP first disconnects the actin from the myosin, and is then hydrolyzed by the myosin in order to produce the energy needed for muscle contraction.
List of limb parts & their representations:
* Elbow joint – Represented by pizza tongs
* Neurons carrying action potentials that trigger muscle – Represented by beef
* Actin-myosin sliding filaments – Represented by the colored lines in straws.
* Bony element – Represented by Styrofoam boxes
* Axon with Schwann cells – Represented by sour punch straws, pixie sticks, and mini back scratchers
* Action potential – Represented by single sour punch straws
* Propagated action potential – Represented by sweet tarts on the sour punch straws, pixie sticks, and mini back scratchers.
* Sarcolemma – Represented by a group of straws and rubber bands
* Sarcomere – Represented by a single straw coming out of a straw bundle
* Calcium binding to myosin – Represented by an M&M attached to single straw
* Myosin crossing bridges – Represented by jelly bracelets and a beaded bracelet
* Muscle belly split into various components – Represented by a bundle of straws, with single straws coming out of the bundle in various colors.
*Muscle – Represented by pepperoni slices
This model represents a movable, flexible limb. This model also shows the elbow joint, and how it makes the arm move. Neurons and muscle cells are also depicted in this model, as well as their specific function in the arm. The essential elements presented in this model include neurons carrying action potentials that trigger muscle (neurotransmitter), actin-myosin sliding filaments, a bony element that muscle attaches to and moves, and a joint that allows for movement.
The neurons presented in this model include axon with schwann cells, movements of charged sodium and potassium ions across the membrane (action potential), and the propagation of action potential along the axon. There are also several aspects of the muscle cells included in this model, such as sarcolemma and T-tubule membranes, a sarcomere, the release of calcium from the Sarcoplasmic reticulum, calcium binding to myosin, and myosin cross-bridges that bring actin filaments together. All of these things put together make a simple limb movement.
Elbow joint – This joint is considered a hinge joint in the body, in which this joint only moves in one direction. This joint is also formed by three bones; the humerus, radius, and ulna and allows the arm to move.
Neurotransmitters – These chemicals are used in order to amplify and relay electrical signals between a neuron and another cell. Within the cell, small neurotransmitter molecules are usually found in vesicles. When action potential occurs, and travels to the synapse, depolarization causes the calcium ion channels to open, which leads to the process of exocytosis.
Actin-myosin sliding filaments – These filaments are responsible for many types of movement in the muscle. Myosin is the prototype of a protein that converts chemical energy in the form of ATP to mechanical energy, in order to create enough force to make the arm move.
Bony element that muscle attaches to – The two ends of the muscle belly are attached to a bone by a muscle tendon. The bone that remains stable during movement is known as the origin, and the bone that moves when the muscle belly contracts in known as insertion. A muscle can make an arm move when insertion occurs, and moves toward the origin, as the muscle belly shortens.
Axon with Schwann cells – Schwann cells speed up and save energy for the processes of action potentials. This variety of neuroglia mainly provides myelin insulation to axons in the peripheral nervous system of our bodies.
Action potential – This process of electrical discharge is very important in order to carry information within and between tissues. This charge travels along the membrane of a cell, and essential in animal and some plant life.
Propagation of action potential – Propagation is the interaction between membrane depolarization and sodium channels. Action potential will propagate in unmyelinated axons, and let sodium ions enter the cell by facilitated diffusion.
Sarcolemma – This is the cell membrane of a muscle cell which receives and conducts stimuli. This membrane is extendable, and encloses different substances from muscle fiber.
Sarcomere – This is the basic unit of a muscle’s myofibril. Sarcomeres are multi-protein complexes which are composed of three different filament systems. The different bands in the sarcomeres allow muscle contraction to occur, and expand and contract in order make the muscle move.
Release of Calcium – This process is important because it lets ATP hydrolysis occur, which supplies energy in the actin-myosin complex. When the action potential triggers a myocyte to contract, calcium ions are able to enter. This calcium actually triggers the release of more calcium ions that are stored in the sarcoplasmic reticulum.
Calcium binding to myosin – This calcium is then able to bind to myosin, after the energy is supplied in the actin-myosin complex. This is needed in order to trigger a contraction of the muscle.
Myosin cross-bridges – During this cycle, actin combines with myosin, and ATP is used to produce force. This ATP first disconnects the actin from the myosin, and is then hydrolyzed by the myosin in order to produce the energy needed for muscle contraction.
List of limb parts & their representations:
* Elbow joint – Represented by pizza tongs
* Neurons carrying action potentials that trigger muscle – Represented by beef
* Actin-myosin sliding filaments – Represented by the colored lines in straws.
* Bony element – Represented by Styrofoam boxes
* Axon with Schwann cells – Represented by sour punch straws, pixie sticks, and mini back scratchers
* Action potential – Represented by single sour punch straws
* Propagated action potential – Represented by sweet tarts on the sour punch straws, pixie sticks, and mini back scratchers.
* Sarcolemma – Represented by a group of straws and rubber bands
* Sarcomere – Represented by a single straw coming out of a straw bundle
* Calcium binding to myosin – Represented by an M&M attached to single straw
* Myosin crossing bridges – Represented by jelly bracelets and a beaded bracelet
* Muscle belly split into various components – Represented by a bundle of straws, with single straws coming out of the bundle in various colors.
*Muscle – Represented by pepperoni slices
The model itself:
I know someone who works at a pizza place, and I was able to use these ingredients to make dough. I made half a batch with 1 ½ cups of oil, ½ cup of salt, 25 lbs of water, 50 lbs of flour, and 4 oz of yeast.
The mixer used to blend all the ingredients
This was the scale used to measure the ingredients
This is the dough when it is finished, and wrapped around a stack of lids in order to make the shape of an arm.
This dough represents the arm and elbow joint, (even though this one is large), and simulates a real arm.
This picture shows the neurons that carry action potentials that trigger muscle, that are found in the elbow joint.
This is a picture of the sarcolemma and its bands
This is a picture of the bone cut from Styrofoam boxes
This is a picture of the axon with schwann cells
This is a picture of the process of action potential, and its propagation represented by sweet tarts.
This is a picture of a single sarcomere
This is a picture of calcium binding to myosin
This is a picture of the muscle belly split into various components
This is a picture of the myosin cross-bridges
This is a picture of the bone being inserted into the dough arm
It took one day for the dough to harden, but it also needed to be stuffed in order to keep its shape.
Here is the elbow joint being inserted into the arm, in order to make it flexible and able to move.
Here is the finished arm. A rubber band is at the bottom of the elbow joint (pizza tongs), make it so the arm can contract and be flexible. 
Here is the finished arm contracting, as you can see the muscle inside the armConclusion:
This model was time consuming, and extremely difficult in showing all the parts of a muscle together inside the arm. I had to do all of the pieces separately, but it all came together and the arm could contract, and was flexible. This lab project was a very interesting experience, and a creative way in learning about the muscle contraction process.
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